Add more options to plot_spikes_hist for HNN-style histograms

[blakecaldwell]

Towards the goal of using hnn-core plots in HNN GUI, plot_spikes_hist() would be a good first example. If a suitable function was availble in hnn-core, it would make spikefn.py one step closer to being deprecated (jonescompneurolab/hnn#237)

The HNN spikefn.plot_hist() has some more parameters that aren't found in viz.plot_spikes_hist() in hnn-core:
https://github.com/jonescompneurolab/hnn/blob/master/spikefn.py#L235-L247

Basically, HNN needs an enhanced plot_spikes_hist() with tstop (xlim), color specification, histtype, linewidth. This could be a separate function for plotting 'bar' histogram types.

hnn-core/hnn_core/viz.py

Lines 51 to 73 in c879ce5

	def plot_spikes_hist(spikes, ax=None, spike_types=None, show=True):
	"""Plot the histogram of spiking activity across trials.
	Parameters
	----------
	spikes : instance of Spikes
	The spikes object from net.spikes
	ax : instance of matplotlib axis | None
	An axis object from matplotlib. If None,
	a new figure is created.
	spike_types: string | list | dictionary | None
	String input of a valid spike type is plotted individually.
	Ex: 'common', 'evdist', 'evprox', 'extgauss', 'extpois'
	List of valid string inputs will plot each spike type individually.
	Ex: ['common', 'evdist']
	Dictionary of valid lists will plot list elements as a group.
	Ex: {'Evoked': ['evdist', 'evprox'], 'External': ['extpois']}
	If None, all input spike types are plotted individually if any
	are present. Otherwise spikes from all cells are plotted.
	Valid strings also include leading characters of spike types
	Example: 'ext' is equivalent to ['extgauss', 'extpois']
	show : bool
	If True, show the figure.

Example calls are in https://github.com/jonescompneurolab/hnn/blob/master/simdat.py#L340-L353

[jasmainak]

I would argue against adding any matplotlib parameters, because users have access to the figure handle. Otherwise, we risk polluting the function signature.

But we can make the defaults match what is there in the GUI, I think that's reasonable.

[blakecaldwell]

I think we should add parameters for bins and color because they cannot easily be changed with the figure handle of a histogram.

[jasmainak]

we could expose **kwargs that gets passed to ax.hist. So any customization the user wants can be done via that.

[aritrasinha108]

@jasmainak is this issue still open?